膦甲酸钠干预高磷诱导的血管平滑肌细胞钙化的研究

目的　观察不同浓度的膦甲酸钠 (PFA)对高磷诱导的牛主动脉血管平滑肌细胞钙沉积和骨钙素 (OC)表达的影响。方法　用不同磷浓度 (正常磷Pi1.5mmol·L-1、高磷Pi2 0mmol·L-1)及含不同浓度膦甲酸钠的培养液 ,体外培养牛主动脉平滑肌细胞 ,观察血管平滑肌细胞钙沉积及骨钙素表达。用甲ο 酚酞络合酮方法测定钙含量 ,BCA法测定蛋白含量。培养上清液中骨钙素浓度用放射免疫法测定 ,用蛋白含量标化钙含量、骨钙素的浓度 ,RT PCR观察骨钙素mR NA的表达。结果　①高磷组较正常磷组平滑肌细胞钙沉积增加 :细胞培养 6d后 ,高磷组 (77 187± 11 6 92 )mg·g-1Pro ,正常磷组 (2 5 76 8± 1 75 0 )mg·g-1Pro ,P <0 0 1;②膦甲酸钠能有效地抑制钙沉积 :培养 6d ,高磷 +PFA 1 0mmol·L-1组 (37 72 9± 5 899)mg·g-1Pro ,与高磷未干预组相比 ,P <0 0 1;③高磷组骨钙素表达明显增高。高磷组与正常磷组相比 ,培养上清液中骨钙素水平 :(1 5 0 3× 10 -2 ±2 6 0 1× 10 -3 )mg·g-1Pro对 (2 981× 10 -3 ± 8 382× 10 -4)mg·g-1Pro ,P <0 0 1;平滑肌细胞骨钙素mRNA表达 (OC/GAPDH) :1 886± 0 16 5对 0 75 2± 0 0 5 2 1,P <0 0 1;④膦甲酸钠能有效地抑制骨钙素的表达。高磷 +PFA 1 0mmol·L-1组与高磷组?     

维拉帕米干预血管钙化作用的研究

目的观察维拉帕米在血管钙化时的作用及机制。方法将SD大鼠随机分为钙化组、维拉帕米组和对照组。5周后测定主动脉ALP、OC、ET水平及钙含量,Von Kossa染色行组织学观察。结果钙化组主动脉ALP、OC、ET水平及钙含量明显增高(P<0.01),主动脉组织中膜弹力纤维间可见大量钙沉积;经维拉帕米治疗后上述指标显著降低(P<0.05),钙沉积减少。结论维拉帕米可能通过抑制内皮素的生成减轻血管钙化的程度。     

小儿腔隙性脑梗死的病因与CT分析

目的探讨小儿腔隙性脑梗死的病因与CT表现。方法对43例腔隙性脑梗死的临床资料进行分析。结果(1)病因:头轻微外伤21例,上呼吸道感染8例,水痘2例,线粒体脑肌病(MELAS),烟雾病1例,系统性红斑狼疮1例,原因不明9例。(2)临床表现:偏瘫41例,失语5例,癫疒间10例,突发性耳聋2例。(3)CT:43例患儿发现51处病灶,其中15例患儿发现一侧或双侧基底节区点状或片状钙化,其附近存在类圆形点或片状低密度灶。(4)预后:40例患儿在12周内症状消失。结论小儿与成人引起腔隙性脑梗死病因不同,预后好。基底节钙化与外伤后急性偏瘫的发生有一定关系。     

Could severity of mitral annular calcification predict other left sided structural or functional abnormalities?

ObjectiveThe prognostic value of MAC severity is important not only because it shares a common risk factors with vascular atherosclerotic changes but also through increasing the cardiovascular morbidity and mortality. This study was conducted in order to evaluate association between severity of MAC and left sided echocardiographic abnormalities mainly left sided valvular abnormalities as well as left atrial systolic and diastolic functional abnormalities.MethodsWe prospectively obtained 12-leads electrocardiograms and transthoracic echocardiograms (TTE) on patients scheduled for non-emergent echocardiographic assessment at tertiary care hospital. MAC was graded as mild, moderate and severe. LA linear dimensions, LA filling and emptying volumes and left atrium ejection fraction were done specifically in addition to commonly measured TTE parameters.ResultsFrom the 80 patients considered for the study, 47 patients had mild MAC, 29 patients had moderate MAC and 4 patients had severe MAC. Valvular affection through echo-doppler assessment that included mainly mitral stenosis, mitral incompetence, aortic sclerosis as well as aortic incompetence showed a highly significant statistical difference (p-values 0.00, 0.00, 0.00 and 0.00 respectively). There was a highly significant statistical difference between patients with different degrees of MAC and LA linear dimension (p-value 0.00), all LA filling and emptying volumes as well as LA ejection fractions with the exception of LA passive emptying volume and LA passive ejection fraction was insignificant.ConclusionsThere is a direct proportionate relationship between severity of MAC and associated left sided valvular affection, increase LA linear dimension as well as lower overall LA function.     

A New Method for in Vitro Calcification Using Acrylamide Gel and Bovine Serum

To investigate the mechanism of biological calcification in vitro a model system consisting of an acrylamide gel block (1×3×3 mm) and fetal bovine serum was developed. Mineral deposition was induced in gel blocks which were immersed in 300 μl of fetal bovine serum at 37°C for 7 days in a CO₂ incubator. X-ray diffraction indicated that the mineral was hydroxyapatite with low crystallinity. Effects of the concentration of acrylamide gel, the partial pressure of CO₂ and matrix proteins within the gel on the mineral formation were investigated. In the gel concentration range of 10–60%, the largest amount of crystal grew in 40% acrylamide gel, where the serum protein did not penetrate. With an increase in the partial pressure of CO₂ the Ca content in the gel block increased, reached the highest level at about 3.5% CO₂ and then began to decrease. In 40% gel and at 5% CO₂ the mineral formation was enhanced by phosvitin, phosphophoryn, demineralized dentin powder and alkaline phosphatase. Mineral deposition occurred around the collagen fibers immobilized in 40% acrylamide gel. These results indicate that 1) a putatively serum-derived inhibitor of calcification with high-molecular weight was prevented from penetrating into the 40% acrylamide gels, 2) immobilized polyanionic proteins and alkaline phosphatase were able to increase mineral deposition and 3) the partial pressure of CO₂ greatly influenced the mineral deposition. It was concluded that this gel system is useful to investigate the mechanism of biological calcification in vitro.     

干扰SET8调节血管平滑肌细胞增殖、凋亡促进血管钙化

背景与目的血管平滑肌细胞(VSMC)凋亡在许多血管钙化疾病的病理过程中起关键作用。近期研究表明,赖氨酸甲基转移酶SET8参与调节细胞增殖、凋亡过程。文章旨在探寻SET8是否通过调节VSMC增殖、凋亡而影响血管钙化。方法体外培养原代大鼠VSMC,将VSMC随机分为正常对照组、空质粒组和SET8-shRNA组。以脂质体Lipofectamine~(TM)2000为载体,转染VSMC。采用茜素红染色法和钙含量测定法判断细胞钙化程度;采用MTT法检测三组细胞的增殖能力;实时荧光定量PCR、Western blot法检测三组细胞中增殖基因Survivin和凋亡基因Caspase-3的表达水平,分析干扰SET8对VSMC增殖、凋亡及其相关基因和蛋白表达的影响。结果 (1)干扰SET8可成功抑制VSMC中SET8蛋白的表达(P0.05)。(2)转染VSMC后,与正常对照组和空质粒组比较,SET8-shRNA组钙含量明显升高(P0.05)。(3)MTT结果显示,在第12 h、24 h、36 h、48 h,SET8-shRNA组VSMC的增殖能力较正常对照组和空质粒组明显降低(P0.05)。(4)实时荧光定量PCR和Western blot结果显示SET8-shRNA组Survivin的mRNA和蛋白表达较正常对照组和空质粒组明显下降,而Caspase-3的mRNA和蛋白表达则相反(P0.05)。结论干扰SET8能够增加促凋亡基因表达,抑制增殖基因表达,SET8有可能参与调节大鼠血管钙化。